title: The intestinal microbiota and susceptibility to infection in immunocompromised patients.
abstract: OBJECTIVE
  Many infections of immunocompromised patients originate from the gastrointestinal tract. The pathogenesis of these infections often begins with alteration of the intestinal microbiota. Understanding the microbiota and how it can either cause or prevent infection is vital for the development of more effective prevention and treatment of these infections. This article reviews and discusses recent work providing insight into the intestinal microbiota of these at-risk immunocompromised patients.
  
  
  RESULTS
  Studies continue to support the premise that commensal bacteria, largely anaerobic, serve to maintain microbial stability and colonization resistance by preventing overgrowth or domination with more pathogenic bacteria, through interactions within the microbial community and with the host. In patients with immune suppression due to high-dose chemotherapy or hematopoietic stem cell transplantation, disruption of the microbiota through antibiotics as well as impairment of host immunity gives rise to perturbations favoring intestinal domination by pathogenic species, leading to increased bacterial translocation and susceptibility to systemic infection.
  
  
  CONCLUSIONS
  An understanding of the intestinal microbiota and the impact of antibiotics will help to guide our treatment of these gut-originating infections.
authors.affiliation: Infectious Diseases, Memorial Sloan Kettering Cancer Center, Sloan Kettering Institute, New York, New York 10065, USA. taury@mskcc.org
authors.forename: Ying
authors.initials: Y
authors.lastname: Taur
authors.forename: Eric G
authors.initials: EG
authors.lastname: Pamer
mesh_terms: D001424:Bacterial Infections / Q000209:etiology* / Q000276:immunology; D041981:Gastrointestinal Tract / Q000382:microbiology*; D054884:Host-Pathogen Interactions / Q000276:immunology; D006801:Humans; D016867:Immunocompromised Host